An electrophoretic display shown in FIG. 11 is known as an electrophoretic device. At least one of substrates 2a and 2b, for example, 2a, is transparent. The transparent substrate 2a has a transparent electrode 4a thereunder and the substrate 2b has an electrode layer 4b thereon, wherein the electrode layer 4b is patterned to have segments each having, for example, a proper shape and size. An electrophoretic microcapsule layer 6a is placed between the transparent substrate 2a and the transparent electrode layer 4b, wherein microcapsules 6 containing a colored dispersion medium having, for example, a black color and charged white pigment particles which function as electrophoretic particles and are dispersed in the dispersion medium are uniformly applied onto the electrophoretic microcapsule layer 6a. For example, when the transparent electrode 4a is grounded and positive or negative voltage is selectively applied to each segment of the electrode layer 4b, a desired image is displayed.
For example, an electrophoretic display using such microcapsules is manufactured according to the following procedure.
The microcapsules 6 containing an electrophoretic dispersion in which pigment particles are dispersed in a colored dispersion medium are prepared. The microcapsules 6 are dispersed in another appropriate dispersion medium to prepare a coating solution. The coating solution is then applied onto a surface of the substrate 2b on which the electrode layer 4b is disposed. The applied coating solution is dried to form the electrophoretic microcapsule layer 6a. The transparent electrode 4a and the transparent substrate 2a are laminated on the electrophoretic microcapsule layer 6a. Thus, the electrophoretic microcapsule layer 6a is disposed between the two substrates 2a and 2b having the transparent electrode 4a and the electrode layer 4b, respectively.
Peripheral circuits such as driving circuits and control circuits and switching elements for selectively supplying voltage to each of the segments of the electrode layer 4b may be mounted to the substrates 2b having the electrode layer 4b. 
Regions for not applying the microcapsules 6 are situated, wherein the regions include portions functioning as electrical contacts between the substrates 2a and 2b and other portions functioning as the peripheral circuits.
As described above, various methods for selectively applying the microcapsules 6 have been proposed, and another method for further selectively applying microcapsules readily and accurately is desired.
The present invention has been developed to solve the above conventional problems. It is an object of the present invention to provide a method for manufacturing an electrophoretic device for selectively forming an electrophoretic layer at a desired region readily and accurately and to provide another method for manufacturing an electronic device using the same.
According to the present invention, in order to accomplish the object, in a first method for manufacturing an electrophoretic device in which an electrophoretic layer including microcapsules containing an electrophoretic dispersion is disposed between two electrodes, the method has the steps of forming lyophobic layers having lyophobicity for the microcapsule dispersion in which the microcapsules are dispersed at desired regions of a member; and applying the microcapsule dispersion onto the member having the lyophobic layers.
In a second method for manufacturing an electrophoretic device according to the present invention, the lyophobic layer on a region used as an electrical contact among the regions has such a thickness that conductivity is obtained in the first method.
In the first and second method for manufacturing an electrophoretic device according to the present invention, the lyophobic layer having lyophobicity for the microcapsule dispersion is formed at a desired region of a member for forming an electrophoretic layer by attaching the microcapsule dispersion in which microcapsules are dispersed, wherein the member is, for example, an electrode. The microcapsule dispersion is then applied onto the member.
Since the lyophobic layer has lyophobicity for the microcapsule dispersion, a microcapsule dispersion portion located on the lyophobic layer is repelled to migrate to another area not having the lyophobic layer; hence the microcapsule dispersion is selectively attached on the member.
In the above state, the lyophobic layer remains on the member. When the region having the lyophobic layer is used as an electrical contact later, the lyophobic layer on the region has such a thickness that conductivity is obtained. Thus, if the region having the lyophobic layer is used as an electrical contact in the state that the lyophobic layer is formed, there are not any problems.
According to the present invention, in a third method for manufacturing an electrophoretic device in which an electrophoretic layer including microcapsules containing an electrophoretic dispersion is disposed between two electrodes, the method has the steps of forming lyophilic layers having lyophilicity for the microcapsule dispersion in which the microcapsules are dispersed at desired regions of a member; and applying the microcapsule dispersion onto the member having the lyophilic layers.
In the third method for manufacturing an electrophoretic device according to the present invention, the lyophilic layer having lyophilicity for the microcapsule dispersion is formed at a desired region of a member for forming an electrophoretic layer by bonding the microcapsule dispersion in which microcapsules are dispersed, wherein the member is, for example, an electrode. The microcapsule dispersion is then applied onto the member.
Since the lyophilic layer has lyophilicity for the microcapsule dispersion, a microcapsule dispersion portion remains on the lyophilic layer. Another microcapsule dispersion portion located on an area not having the lyophilic layer gravitates toward the lyophilic layer. Subsequently, the microcapsule dispersion portion is selectively applied onto the region having the lyophilic layer.
In the fourth method for manufacturing an electrophoretic device according to the present invention, the microcapsule dispersion contains a binder according to any one of the first to third methods for manufacturing an electrophoretic device of the present invention.
In the fourth method for manufacturing an electrophoretic device according to the present invention, since the microcapsule dispersion containing dispersed microcapsules therein further contains a binder, the binder causes the microcapsules to bond to the member surely.
In the fifth method for manufacturing an electrophoretic device according to the present invention, a migration-promoting operation for promoting migration of the microcapsule dispersion on the member is performed while or after applying the microcapsule dispersion onto the member according to any one of the first to fourth methods for manufacturing an electrophoretic device of the present invention.
In the fifth method for manufacturing an electrophoretic device according to the present invention, while or after applying the microcapsule dispersion onto the member or in both states, a migration-promoting operation for promoting migration of the microcapsule dispersion on the member is performed as follows: the member is vibrated in the back, forth, right, and left directions, or inclined, or an air flow is applied. Thus, the microcapsule dispersion portion applied onto the member is ready to migrate to an area not having the lyophobic layer or a region having the lyophilic layer; hence the microcapsule dispersion is applied even more surely and selectively.
According to the present invention, in the sixth method for manufacturing an electrophoretic device in which electrophoretic particles contained in microcapsules migrate in response to voltage applied from electrodes, the method has the steps of forming lyophobic layers having lyophobicity for the microcapsule dispersion in which the microcapsules are dispersed at desired regions of a member; and applying the microcapsule dispersion onto the member having the lyophobic layers.
In the seventh method for manufacturing an electrophoretic device according to the present invention, the lyophobic layer on a region used as an electrical contact among the regions has such a thickness that conductivity is obtained in the first method.
According to the present invention, in the eighth method for manufacturing an electrophoretic device in which electrophoretic particles contained in microcapsules migrate in response to voltage applied from electrodes, the method has the steps of forming lyophilic layers having lyophilicity for the microcapsule dispersion in which the microcapsules are dispersed at desired regions of a member; and applying the microcapsule dispersion onto the member having the lyophilic layers.
In the ninth method for manufacturing an electrophoretic device according to present invention, the microcapsule dispersion contains a binder according to any one of the sixth to eight methods for manufacturing an electrophoretic device of the present invention.
In the tenth method for manufacturing an electrophoretic device according to the present invention, a migration-promoting operation for promoting migration of the microcapsule dispersion on the member is performed while or after applying the microcapsule dispersion onto the member according to any one of the sixth to ninth methods for manufacturing an electrophoretic device of the present invention.
In the sixth to tenth methods for manufacturing an electrophoretic device of the present invention, the same effects as those of the first to fifth methods for manufacturing an electrophoretic device of the present invention is obtained.
According to the present invention, in a method for manufacturing an electronic device having an electrophoretic device, the method has the steps of forming wiring comprising a conductive material on a substrate, and manufacturing the electrophoretic device by the method for manufacturing an electrophoretic device according to any one of claims 1 to 10.
The method for manufacturing an electronic device of the present invention includes the step of manufacturing an electrophoretic device by the method for manufacturing an electrophoretic device according to the present invention. Thus, an electronic device having an electrophoretic device in which a microcapsule dispersion is readily selectively applied is obtained.